集水面积阈值确定方法在嘉陵江流域的比较应用

Application and comparison of identification methods for critical catchment area threshold in Jialing River Basin

为探讨集水面积阈值确定方法用于不同流域面积、不同地形地貌特征流域的差异性和适用性,将河网密度法、适度指数法和分形维数法3种常用的集水面积阈值确定方法应用于嘉陵江流域。结果表明:河网密度法方法简单,对下垫面分布均匀、地形起伏度较大的地区模拟效果更好;适度指数法对地形起伏度较大的区域模拟效果较好,计算结果受缓冲半径的影响;分形维数法模拟效果不稳定,不适用于面积和地形起伏度较大且河道多弯曲的流域。研究结果可为嘉陵江流域水系提取时阈值的选取提供依据。

In order to analyze and compare the diversity and practicability of several identification methods for critical catch-ment area threshold in the basin areas of different catchment areas and landforms, three widely - used identification methods, in-cluding drainage network density method, fitness index method and fractal theory method, were applied in the Jialing River Ba-sin. The results show that the drainage network density method is simple and simulates better in the homogeneous underlying sur-face and large landform amplitude area; fitness index method extracts better drainage networks in large landform amplitude area but is influenced by the buffer radius; the simulation results of fractal theory method is unsteady and the method is not applicable in the river with large area, large landform amplitude and tortuous channels.